Abstract: A two-dimensionally scannable antenna system for transmission or receiving a microwave beam over a wide angular region, using multiple parallel plate lenses for focusing and to provide, in conjunction with a like number of phase shifters, scanning of the beam in one transverse direction, such as in azimuth. The multiple parallel plate lenses provide output signals for processing by a single diode grid lens, which provides for deflection of the beam about the other transverse axis, to scan the beam in elevation. The diode grid lens includes parallel conductive plates with a thickness tapered from a minimum value near the input and output of the diode grid lens, to a maximum value over most of the length of the diode grid lens. This increased thickness of the plates reduces the required number of switchable diodes in the diode grid lens. The device of the invention has fewer components, lower power consumption and corresponding lower cost than similar configurations available prior to the present invention.

Abstract: A field-effect transistor (FET) and a corresponding method for its fabrication, the transistor having a source and a gate located at opposite faces of an active channel region formed in a substrate, the source being substantially shorter in effective length than the gate and located symmetrically with respect to the gate. The transistor also has two drains, located one at each end of the channel region, and charge carriers flow from the source to the drains in two paths, under control of the same gate. Electrical contact with the source is made from beneath the substrate, while contact with the gate and drains is made from above. The resulting device has a large incremental transconductance and relatively small parasitic impedances, and therefore can operate at much higher frequencies than conventional FET's.